JP7070258B2 - Crane and crane control method - Google Patents

Description

The present invention relates to a crane and a crane control method.

In a crane that drives a winch with a hydraulic motor, the flow rate of the hydraulic oil in the winding direction is applied to the flow path of the hydraulic oil so that the speed of the winch (descent speed of the suspended load) does not become too large due to the weight of the suspended load during unwinding. A configuration provided with a limiting counterbalance valve is widely adopted (for example, Japanese Patent Application Laid-Open No. 2001-10785).

The counterbalance valve opens the flow path when the primary side pressure of the hydraulic oil supplied to the hydraulic motor increases to some extent during unwinding, so that the hydraulic oil can be discharged from the hydraulic motor to the secondary side. It is composed. Hydraulic oil is supplied to the hydraulic motor via a control valve whose opening degree is determined according to the angle of the operating lever operated by the operator. Therefore, the operator can adjust the opening degree of the counterbalance valve by adjusting the pressure of the hydraulic oil supplied to the hydraulic motor by operating the operation lever to adjust the speed of the winch at the time of winding down. can.

In recent years, for example, the maximum weight of a suspended load of a crane has been increasing due to shortening of the construction period. When the weight of the suspended load becomes large, the difference between the winding speed and the winding speed when the operation of the operating lever is constant becomes large, so that the operability of the winch may be insufficient.

In addition, due to such a decrease in operability, when the weight of the suspended load is heavy, the operator cannot properly adjust the winding speed by the operation lever, and the winding speed becomes excessively high and passes through the counterbalance valve. The calorific value may temporarily increase as the flow rate of the hydraulic oil increases. The increase in heat generation in the counterbalance valve causes the temperature of the hydraulic oil to rise, so that the air volume of the fan for cooling the hydraulic oil increases, which causes inconveniences such as noise generation and an increase in energy consumption. Further, if the capacity of the oil cooler is increased to cope with the heat generation of the hydraulic oil, not only the equipment cost increases but also the layout becomes difficult due to the increase in size of the oil cooler.

Japanese Unexamined Patent Publication No. 2001-10785

In view of the above inconvenience, it is an object of the present invention to provide a crane and a crane control method capable of suppressing a decrease in operability when the weight of a suspended load is large.

The crane according to the present invention made to solve the above problems includes an engine, a hydraulic pump driven by the engine, a hydraulic motor operated by the hydraulic oil supplied from the hydraulic pump, and a winch. It is provided in the counterbalance valve provided in the flow path for supplying and discharging the hydraulic oil to the hydraulic motor and in the flow path for supplying and discharging the hydraulic oil to the hydraulic motor, and the opening degree is changed according to the operation amount of the operator. A crane equipped with a winch drive system having a control valve, and provided with a control mechanism for adjusting the output of the winch drive system at the time of winding according to the speed of the winch with respect to the operation amount of the operator at the time of winding. It is characterized by.

The crane is equipped with a control mechanism that adjusts the output of the winch drive system at the time of unwinding according to the speed of the winch with respect to the operation amount of the operator at the time of hoisting, so that the crane is counterbalanced when the weight of the suspended load is heavy. It is possible to suppress an increase in the flow rate of the hydraulic oil passing through the valve. That is, in the crane, the heavier the weight of the suspended load, the smaller the speed of the winch with respect to the operation amount of the operator at the time of hoisting. By adjusting the output of the drive system, it is possible to prevent the speed at the time of winding down the winch from increasing significantly compared to the speed at the time of winding up, and to suppress a decrease in operability. Further, in the crane, heat generation is reduced by suppressing an increase in the flow velocity of the hydraulic oil in the counterbalance valve, so that the noise and energy consumption of the cooling fan can be reduced.

In the crane, the control mechanism is based on the speed of the winch with respect to the operation amount of the operator at the time of hoisting, and the speed at the time of hoisting and the winding of the winch assumed when the operation amount of the operator is constant. The output of the winch drive system may be adjusted so that the difference from the speed of time is within a predetermined range. As described above, the control mechanism is based on the speed of the winch with respect to the operation amount of the operator at the time of winding, and the speed at the time of winding and the winding of the winch assumed when the operation amount of the operator is constant. By adjusting the output of the winch drive system so that the difference from the speed at the time is within a predetermined range, the operator does not make a big difference in the operation amount between winding and unwinding, and it feels almost the same. Can be operated.

In the crane, the control mechanism may reduce the output of the winch drive system at the time of winding so that the speed of the winch with respect to the operation amount of the operator at the time of winding is smaller. In this way, the control mechanism reduces the output of the winch drive system during winding as the speed of the winch with respect to the operation amount of the operator during winding decreases, so that the weight of the suspended load is increased. Operability can be improved by reducing the output of the winch drive system at the time and reducing the difference between the speed at which the winch is wound and the speed at which the winch is unwound.

In the crane, the control mechanism may adjust the engine speed. In this way, by adjusting the rotation speed of the engine by the control mechanism, when the weight of the suspended load is heavy, the flow velocity of the hydraulic oil passing through the counterbalance valve at the time of unwinding is increased, and the temperature of the hydraulic oil is increased accordingly. The rise can be suppressed and the fuel consumption of the engine can be effectively suppressed.

In the crane, the control mechanism may adjust the capacity of the hydraulic pump. In this way, the control mechanism adjusts the capacity of the hydraulic pump to change the pressure of the hydraulic oil supplied to the hydraulic motor, and the hydraulic oil passes through the counterbalance valve when the weight of the suspended load is heavy. The increase in the hydraulic pressure can be easily and surely suppressed.

In the crane, the control mechanism may adjust the capacity of the hydraulic motor. In this way, the control mechanism adjusts the capacity of the hydraulic motor to change the amount of hydraulic oil discharged from the hydraulic motor according to the weight of the suspended load, so that the counterbalance valve can be used when the weight of the suspended load is large. It is possible to easily and surely suppress an increase in the flow rate of the hydraulic oil passing through.

In the crane, the control mechanism may adjust the correspondence between the operation amount of the operator and the opening degree of the control valve. In this way, the control mechanism adjusts the correspondence between the operation amount of the operator and the opening degree of the control valve, so that the degree of adjustment of the primary pressure by the control valve is optimized according to the weight of the suspended load. Therefore, it is possible to easily and surely suppress an increase in the flow rate of hydraulic oil passing through the counterbalance valve when the weight of the suspended load is large.

In the crane, the control mechanism may determine the speed of the winch based on the pressure and flow rate of the hydraulic oil supplied to the hydraulic motor. In this way, the control mechanism determines the speed of the winch based on the pressure and the flow rate of the hydraulic oil supplied to the hydraulic motor, so that the speed can be grasped relatively accurately even when the speed of the winch is low. be able to.

In the crane, the control mechanism does not have to adjust the output of the winch drive system when the operation amount of the operator is small. As described above, the control mechanism does not adjust the output of the winch drive system when the operation amount of the operator is small, so that the operation amount is sufficiently reduced when the operator has a large weight of the suspended load. By superimposing and suppressing the output of the winch drive system, it is possible to prevent the suspension speed from being excessively lowered.

The method for controlling a crane according to the present invention is an engine, a hydraulic pump driven by the engine, a hydraulic motor operated by the hydraulic oil supplied from the hydraulic pump to drive a winch, and hydraulic oil for the hydraulic motor. It has a counterbalance valve provided in the flow path for supplying and discharging hydraulic oil, and a control valve provided in the flow path for supplying and discharging hydraulic oil to the hydraulic motor and whose opening degree is changed according to the operation amount of the operator. It is a control method of a crane provided with a winch drive system, and is characterized in that the output of the winch drive system at the time of winding is adjusted according to the speed of the winch with respect to the operation amount of the operator at the time of winding.

The control method of the crane is a counterbalance valve when the weight of the suspended load is heavy by adjusting the output of the winch drive system at the time of winding according to the speed of the winch with respect to the operation amount of the operator at the time of winding. It is possible to suppress an increase in the flow rate of the hydraulic oil passing through the water and suppress a decrease in operability.

As described above, the crane and the crane control method according to the present invention can suppress an increase in the flow rate of hydraulic oil passing through the counterbalance valve when the weight of the suspended load is large.

It is a hydraulic circuit diagram which shows the structure about the winch drive system of the crane of one Embodiment of this invention. It is a flowchart which shows the control flow of the control mechanism of the crane of FIG. It is a hydraulic circuit diagram which shows the structure about the winch drive system of the crane of the embodiment different from FIG. 1 of this invention. It is a hydraulic circuit diagram which shows the structure about the winch drive system of the crane of the embodiment different from FIGS. 1 and 3 of this invention. It is a hydraulic circuit diagram which shows the structure about the winch drive system of the crane of the embodiment different from FIGS. 1, 3 and 4 of this invention. It is a hydraulic circuit diagram which shows the structure about the winch drive system of the crane of the embodiment different from FIGS. 1, 3 and 5 of this invention. It is a flowchart which shows the control flow of the control mechanism of the crane of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[First Embodiment]
As shown in FIG. 1, the crane according to the embodiment of the present invention includes a winch drive system 1 for driving the winch W and a control mechanism 2 for controlling the output of the winch drive system 1.

The winch drive system 1 is operated by the engine 11, the hydraulic pump 12 driven by the engine 11, the hydraulic oil supplied from the hydraulic pump 12, and the hydraulic motor 13 for driving the winch W, and the hydraulic motor 13. It has a counterbalance valve 14 provided in a flow path for supplying and discharging hydraulic oil, and a control valve 15 provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor 13.

The control mechanism 2 is a winch drive at the time of winding according to the speed of the operation lever 16 operated by the operator to adjust the opening degree of the control valve 15 and the winch W with respect to the operation amount of the operation lever 16 by the operator at the time of winding. It has a controller 17 that adjusts the output of the system 1.

The control performed by the controller 17 is an embodiment of the crane control method of the present invention. That is, the crane control method according to the present embodiment is a method of adjusting the output of the winch drive system 1 at the time of winding according to the speed of the winch W with respect to the operation amount of the operation lever 16 by the operator at the time of winding.

<Engine>
As the engine 11, for example, a known internal combustion engine that converts heat energy generated by combustion of fuel such as a diesel engine or a gasoline engine (Ottocycle engine) into rotational energy of a crankshaft can be used. The engine 11 is autonomously controlled so as to be operated at a rotation speed set from the outside.

<Hydraulic pump>
The hydraulic pump 12 is a pump driven by an engine 11 that pressurizes and delivers hydraulic oil. As the hydraulic pump 12, for example, a piston pump, a vane pump, a gear pump, a screw pump and the like can be used, and among them, a swash plate type axial piston pump is preferably used.

<Hydraulic motor>
The hydraulic motor 13 is driven by the hydraulic oil supplied from the hydraulic pump 12 to rotate the winch W. As the hydraulic motor 13, for example, a plunger motor, a gear motor, a vane motor, or the like can be used, and among them, a swash plate type axial plunger motor is preferably used. In the figure, the hydraulic oil passes through the hydraulic motor 13 from top to bottom during winding, and the hydraulic oil passes through the hydraulic motor 13 from bottom to top during winding.

<Counter balance valve>
The counterbalance valve 14 applies back pressure to the hydraulic oil discharge flow path (secondary side flow path) when the hydraulic pump 12 is unwound, and the suspended load pulls out the rope from the winch W due to its weight and descends at high speed. It is provided to prevent this from happening. Specifically, the counterbalance valve 14 urges the spool that opens and closes the flow path with a spring so that the spool can be moved by the pressure of the hydraulic oil discharge flow path and the supply flow path to open the flow path. The spring urging force is set so as to open the flow path when the pressure of the supply flow path (primary side flow path) rises without opening the flow path only by the weight of the suspended load.

<Control valve>
As the control valve 15, the supply direction of the hydraulic oil to the hydraulic pump 12 can be selected, and the open state and the closed state of the flow path can be alternately switched in a short time to adjust the ratio of the open state time. A known proportional control valve that can be used can be used. The proportional control valve may have an opening degree proportional to, for example, the current value of the input signal, that is, a ratio of time for opening the flow path of the hydraulic oil may be proportional to the input signal.

<Operating lever>
The operation lever 16 outputs an operation amount by the operator, for example, its inclination angle and inclination direction as a signal, and inputs it to the control valve 15.

<Controller>
The controller 17 is configured to input a signal for designating the opening degree to the control valve 15 according to the output signal of the operation lever 16 and to change the set value of the rotation speed of the engine 11. The controller 17 changes the set value of the rotation speed of the engine 11 at the time of winding down based on the speed of the winch W at the time of winding up and the operation amount of the operation lever 16.

The controller 17 inputs a signal for designating the opening degree to the control valve 15 according to the output signal of the operation lever 16, and at the time of winding down according to the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding up. It is configured to adjust the rotation speed of the engine 11. Specifically, the controller 17 adjusts the set value of the rotation speed of the engine 11 so that the output of the winch drive system 1 at the time of winding becomes smaller as the speed of the winch with respect to the operation amount of the operator at the time of winding becomes smaller. do.

The speed of the winch W at the time of winding increases as the operation amount of the operation lever 16 increases and the weight of the suspended load decreases. Therefore, the magnitude of the speed of the winch W at the time of winding with respect to the operation amount of the operation lever 16 can be considered as an index representing the weight of the suspended load.

Further, assuming that the operation amount of the operation lever 16 is constant, the speed at the time of winding becomes higher than that at the time of winding due to the weight of the suspended load. At this time, the heavier the weight of the suspended load, the greater the decrease in the speed at the time of winding with respect to the speed at the time of winding. Therefore, if it is considered that the speed of the winch W at the time of winding is relatively low and the weight of the suspended load is large, the rotation speed of the engine 11 is set to a low value at the time of winding, and the hydraulic pressure is applied from the hydraulic pump 12. By suppressing the pressure of the hydraulic oil supplied to the motor 13, it is possible to prevent the winding speed of the winch W from becoming too high.

In this way, by preventing the winding speed of the winch W from becoming too high, it is possible to prevent the calorific value of the hydraulic oil in the counterbalance valve 14 from temporarily increasing. This prevents a temporary excessive load from being applied to the hydraulic oil cooling mechanism, suppresses noise and energy consumption by the fan for cooling the hydraulic oil, and stabilizes the temperature of the hydraulic oil. Can be controlled. Further, by setting the rotation speed of the engine 11 to be low by the controller 17, the fuel consumption in the engine 11 can be suppressed.

FIG. 2 shows a procedure for controlling the rotation speed of the engine 11 by the control mechanism 2 including the controller 17. The controller 17 monitors the operation direction and the operation amount of the operation lever 16. Whether it is winding up or down can be determined by the operating direction of the operating lever 16.

The controller 17 confirms the rotation speed of the winch W at the time of winding. The speed of the winch W is based on the detected values of the pressure sensor 18 and the flow rate sensor 19 provided in the flow path for supplying the hydraulic oil to the hydraulic motor 13, that is, the pressure and the flow rate of the hydraulic oil supplied to the hydraulic motor 13. Judgment is based on. As the pressure sensor 18 and the flow rate sensor 19, known sensors capable of outputting a detection signal can be used.

The speed of the winch W can be determined relatively accurately by deriving the rotational speed of the hydraulic motor 13 from the pressure and flow rate of the hydraulic oil based on the performance curve of the hydraulic motor 13. Further, the controller 17 may store a table in which the performance curve of the hydraulic motor 13 is simplified, and may gradually recognize the speed of the winch W as belonging to any of a plurality of speed ranges.

The speed of the winch W at the time of winding is preferably measured when the operating lever 16 is operated in the winding direction by a certain amount or more, and the state in which the operating lever 16 is operated in the winding direction by a certain amount or more is continued for a certain period of time or more. It is more preferable to calculate only in the case (when the maximum operation amount is substantially held for a certain period of time or longer).

Then, the controller 17 calculates the speed of the winch W with respect to the operation amount of the operation lever 16 within this operation time. Specifically, the controller 17 can be configured to calculate the proportionality constant or the like assuming that the speed of the winch W is proportional to the operation amount of the operation lever 16. Further, when the speed of the winch W is measured only when the operation amount of the operation lever 16 is substantially the maximum amount, a value obtained by simply averaging the speed of the winch W over time may be calculated.

The speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding is referred to for determining the rotation speed of the engine 11 when the operation lever 16 is operated in the winding direction. Specifically, the controller 17 stores a reference table showing the correspondence between the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding and the appropriate rotation speed of the engine 11 at the time of winding. The reference table can be used to configure the engine 11 to determine the number of revolutions at the time of winding.

The controller 17 stores the rotation speed of the engine 11 determined based on the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding, and refers to it when the operation lever 16 is operated in the winding direction. Further, the controller 17 stores the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding, and the operation lever 16 at the time of winding which is stored when the operation lever 16 is operated in the winding direction. The rotation speed of the engine 11 may be determined based on the speed of the winch W with respect to the operation amount.

The speed of the winch W or the rotation speed of the engine 11 at the time of winding is stored until the operating lever 16 is operated in the winding direction by a certain amount or more and for a certain period of time or more, and the operating lever 16 is operated in the winding direction. Can be referenced for setting the engine speed of the case. As a result, it is possible to prevent the winch W from unnecessarily changing the speed with respect to the operation amount of the operation lever 16 and deteriorating the operability when the hoisting and lowering are repeated in order to position the suspended load. Further, for example, when the operation lever 16 is not operated for a certain period of time or when the winch W brake is used, the stored winding speed may be reset.

The controller 17 may reduce the rotation speed of the engine 11 so that the speed at which the winch W is wound down and the speed at which the winch W is wound up are substantially equal when the amount of operation of the operation lever 16 by the operator is constant. If the rate of increase of the winch W at the time of winding down with respect to the speed at the time of winding up can be suppressed to some extent, a sufficient effect of improving operability and an effect of preventing hydraulic oil heat generation can be obtained. Therefore, in the controller 17, when the operation amount of the operation lever 16 by the operator is constant, the difference between the winding speed and the winding speed of the winch W is within a predetermined range. It is preferable to control the rotation speed.

[Second Embodiment]
As shown in FIG. 3, the crane according to another embodiment of the present invention includes a winch drive system 1a for driving the winch W and a control mechanism 2a for controlling the output of the winch drive system 1a.

The winch drive system 1a is operated by the engine 11, the hydraulic pump 12a driven by the engine 11, the hydraulic oil supplied from the hydraulic pump 12a, and the hydraulic motor 13 for driving the winch W, and the hydraulic motor 13. It has a counterbalance valve 14 provided in a flow path for supplying and discharging hydraulic oil, and a control valve 15 provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor 13.

The control mechanism 2a includes an operation lever 16 operated by the operator and a controller 17a that adjusts the capacity of the hydraulic pump 12a according to the speed of the winch W with respect to the operation amount of the operation lever 16 by the operator at the time of winding. A pressure sensor 18 and a flow rate sensor 19 are provided in the flow path for supplying hydraulic oil to the hydraulic motor 13 in order to confirm the speed of the winch W.

In the crane of FIG. 3, the engine 11, the hydraulic motor 13, the counterbalance valve 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow sensor 19 are the engine 11, the hydraulic motor 13, and the counterbalance valve in the crane of FIG. 14, the control valve 15, the operation lever 16, the pressure sensor 18, and the flow sensor 19. Therefore, with respect to the crane of FIG. 3, the same components as those of the crane of FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

<Hydraulic pump>
The hydraulic pump 12a has a variable capacity. Examples of the hydraulic pump 12a include a swash plate type axial piston type variable displacement pump and the like. In the swash plate type axial piston type variable capacity pump, by changing the tilt angle of the swash plate, the stroke of the piston changes and the capacity (hydraulic oil discharge amount per input rotation speed) increases or decreases.

It is preferable that the hydraulic pump 12a has an actuator for changing the capacity, and the capacity can be set by designating the position of the actuator by an external signal.

<Controller>
The controller 17a inputs a signal for designating the opening degree to the control valve 15 according to the output signal of the operation lever 16, and at the time of winding down based on the speed of the winch W at the time of winding up and the operation amount of the operation lever 16. It is configured to change the capacity of the hydraulic pump 12a. Specifically, the controller 17a reduces the capacity of the hydraulic pump 12a at the time of winding down as the speed of the winch W with respect to the operation amount of the operating lever 16 at the time of winding up is small.

Specifically, the controller 17a selects the capacity of the hydraulic pump 12a according to the speed of the winch W at the time of winding with reference to a predetermined reference table, and specifies the position of the actuator for adjusting the capacity of the hydraulic pump 12a. Can be configured to output the signal to be output.

By adjusting the capacity of the hydraulic pump 12a in this way, it is possible to suppress an increase in the speed at which the winch W is wound down with respect to the speed at which the winch W is wound up. Is obtained.

The above-mentioned control performed by the controller 17a of the present embodiment is an embodiment of the crane control method according to the present invention.

[Third Embodiment]
As shown in FIG. 4, the crane according to another embodiment of the present invention includes a winch drive system 1b for driving the winch W and a control mechanism 2b for controlling the output of the winch drive system 1b.

The winch drive system 1b is operated by the engine 11, the hydraulic pump 12 driven by the engine 11, the hydraulic oil supplied from the hydraulic pump 12, and the hydraulic motor 13b for driving the winch W, and the hydraulic motor 13b. It has a counterbalance valve 14 provided in a flow path for supplying and discharging hydraulic oil, and a control valve 15 provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor 13b.

The control mechanism 2b includes an operation lever 16 operated by the operator and a controller 17b that adjusts the capacity of the hydraulic motor 13b according to the speed of the winch W with respect to the operation amount of the operation lever 16 by the operator at the time of winding. A pressure sensor 18 and a flow rate sensor 19 are provided in the flow path for supplying hydraulic oil to the hydraulic motor 13b in order to confirm the speed of the winch W.

In the crane of FIG. 4, the engine 11, the hydraulic pump 12, the counterbalance valve 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow sensor 19 are the engine 11, the hydraulic pump 12, and the counterbalance valve in the crane of FIG. The same applies to 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow rate sensor 19. Therefore, with respect to the crane of FIG. 4, the same components as those of the crane of FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

<Hydraulic pump>
The hydraulic motor 13b has a variable capacity. Examples of the hydraulic motor 13b include a swash plate type axial plunger type variable displacement motor. In the swash plate type axial plunger type variable capacity motor, by changing the tilt angle of the swash plate, the stroke of the plunger changes and the capacity (output rotation speed with respect to the hydraulic oil flow rate) increases or decreases.

It is preferable that the hydraulic motor 13b has an actuator for changing the capacity, and the capacity can be set by designating the position of the actuator by an external signal.

<Controller>
The controller 17b inputs a signal for designating the opening degree to the control valve 15 according to the output signal of the operation lever 16, and at the time of winding down based on the speed of the winch W at the time of winding up and the operation amount of the operation lever 16. It is configured to change the capacity of the hydraulic motor 13b. Specifically, in the controller 17b, the smaller the speed of the winch W with respect to the operation amount of the operating lever 16 at the time of winding, the larger the capacity of the hydraulic motor 13b at the time of winding.

Specifically, the controller 17b selects the capacity of the hydraulic motor 13b according to the speed of the winch W at the time of winding with reference to a predetermined reference table, and specifies the position of the actuator for adjusting the capacity of the hydraulic motor 13b. Can be configured to output the signal to be output.

By adjusting the capacity of the hydraulic motor 13b in this way, it is possible to suppress an increase in the speed at which the winch W is wound down with respect to the speed at which the winch W is wound up. Is obtained.

The above-mentioned control performed by the controller 17b of the present embodiment is an embodiment of the crane control method according to the present invention.

[Fourth Embodiment]
As shown in FIG. 5, the crane according to another embodiment of the present invention includes a winch drive system 1 for driving the winch W and a control mechanism 2c for controlling the output of the winch drive system 1.

The winch drive system 1 is operated by the engine 11, the hydraulic pump 12 driven by the engine 11, the hydraulic oil supplied from the hydraulic pump 12, and the hydraulic motor 13 for driving the winch W, and the hydraulic motor 13. It has a counterbalance valve 14 provided in a flow path for supplying and discharging hydraulic oil, and a control valve 15 provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor 13.

The control mechanism 2c adjusts the correspondence between the operation lever 16 operated by the operator and the operation amount of the operation lever 16 and the opening degree of the control valve 15 according to the speed of the winch W with respect to the operation amount of the operation lever 16 by the operator. It has a controller 17c. A pressure sensor 18 and a flow rate sensor 19 are provided in the flow path for supplying hydraulic oil to the hydraulic motor 13 in order to confirm the speed of the winch W.

In the crane of FIG. 5, the engine 11, the hydraulic pump 12, the hydraulic motor 13, the counterbalance valve 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow rate sensor 19 are the engine 11 and the hydraulic pump 12 in the crane of FIG. , The hydraulic motor 13, the counterbalance valve 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow rate sensor 19. Therefore, with respect to the crane of FIG. 5, the same components as those of the crane of FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

<Controller>
The controller 17c inputs a signal for designating the opening degree to the control valve 15 according to the output signal of the operation lever 16, and the smaller the speed of the winch W with respect to the operation amount of the operation lever 16 by the operator at the time of winding, the more the winding. It is configured to adjust the output signal level for the control valve 15 so that the opening degree of the control valve 15 with respect to the operation amount of the operation lever 16 becomes smaller when the lever 16 is lowered.

The controller 17c may store a reference table showing the relationship between the operation amount of the operation lever 16 and the output signal level for the control valve 15. In this case, a plurality of reference tables corresponding to the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding are stored, and a reference table to be applied according to the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding is stored. By selecting, the output signal level for the control valve 15 may be adjusted.

In this way, by adjusting the opening degree of the control valve 15 with respect to the operation amount of the operation lever 16, it is possible to suppress the increase in the winding speed of the winch W experienced by the operator with respect to the winding speed. , The operability can be improved.

The above-mentioned control performed by the controller 17c of the present embodiment is an embodiment of the crane control method according to the present invention.

[Fifth Embodiment]
As shown in FIG. 6, the crane according to another embodiment of the present invention includes a winch drive system 1 for driving the winch W and a control mechanism 2d for controlling the output of the winch drive system 1.

The winch drive system 1 is operated by the engine 11, the hydraulic pump 12 driven by the engine 11, the hydraulic oil supplied from the hydraulic pump 12, and the hydraulic motor 13 for driving the winch W, and the hydraulic motor 13. It has a counterbalance valve 14 provided in a flow path for supplying and discharging hydraulic oil, and a control valve 15 provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor 13.

The control mechanism 2d includes an operation lever 16 operated by the operator and a controller 17d that adjusts the capacity of the hydraulic pump 12d according to the speed of the winch W with respect to the operation amount of the operation lever 16 by the operator at the time of winding. In order to confirm the speed of the winch W, a pressure sensor 18 and a flow rate sensor 19 are provided in the flow path for supplying hydraulic oil to the hydraulic motor 13 at the time of winding. Further, a second pressure sensor 20 for detecting the supply pressure of the hydraulic oil from the control valve 15 to the hydraulic motor 13 is provided in the flow path for supplying the hydraulic oil to the hydraulic motor 13 at the time of winding down.

In the crane of FIG. 6, the engine 11, the hydraulic pump 12, the hydraulic motor 13, the counterbalance valve 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow sensor 19 are the engine 11 and the hydraulic pump 12 in the crane of FIG. , The hydraulic motor 13, the counterbalance valve 14, the control valve 15, the operating lever 16, the pressure sensor 18, and the flow rate sensor 19. Therefore, with respect to the crane of FIG. 6, the same components as those of the crane of FIG. 1 are designated by the same reference numerals, and duplicate description will be omitted.

<Controller>
The controller 17d inputs a signal for designating the opening degree to the control valve 15 according to the output signal of the operation lever 16, and at the time of winding down based on the speed of the winch W at the time of winding up and the operation amount of the operation lever 16. It is configured to change the rotation speed of the engine 11. Specifically, the controller 17d reduces the rotation speed of the engine 11 at the time of winding down as the speed of the winch W with respect to the operation amount of the operation lever 16 at the time of winding up is small.

However, the controller 17d does not adjust the rotation speed of the engine 11 at the time of winding down when the operation amount of the operation lever 16 is small. Specifically, when the pressure of the hydraulic oil supplied from the control valve 15 to the hydraulic motor 13 at the time of winding down, that is, the detection value of the second pressure sensor 20 is smaller than a predetermined threshold value, the operation amount of the operation lever 16 Since it can be determined that the opening degree of the control valve 15 is small because the pressure is small, it is preferable that the controller 17d does not set the rotation speed of the engine 11 to a value determined by the winding speed.

FIG. 7 shows a detailed procedure for controlling the rotation speed of the engine 11 by the control mechanism 2 including the controller 17d. The control procedure of FIG. 7 is the same as the control procedure of FIG. 2 except that the procedure referred to below is included. Therefore, the description of the control procedure of FIG. 7 that overlaps with the control procedure of FIG. 2 will be omitted.

In the control of FIG. 7, when the lever operation is in the winding direction in the control of FIG. 2, the pressure of the hydraulic oil supplied to the hydraulic motor 13 by the second pressure sensor 20 is confirmed, and the pressure of the hydraulic oil is predetermined. If it does not reach the threshold value, the process of setting the rotation speed of the engine 11 according to the speed at the time of winding, which stores the set value of the rotation speed, is not performed.

In the crane of the present embodiment, when the operation amount of the operation lever 16 at the time of lowering is small, a skilled operator can sufficiently reduce the operation amount of the operation lever 16 and appropriately adjust the speed of the suspended load. Therefore, it is possible to prevent the controller 17d from being superimposed and reducing the output of the winch drive system 1 to excessively suppress the speed of the suspended load.

The above-mentioned control performed by the controller 17d of the present embodiment is an embodiment of the crane control method according to the present invention.

[Other embodiments]
The above embodiment does not limit the configuration of the present invention. Therefore, the above-described embodiment can be omitted, replaced or added with components of each part of the above-described embodiment based on the description of the present specification and the common general technical knowledge, and all of them are construed to belong to the scope of the present invention. Should be.

In the crane and the control method of the crane, the speed of the winch may be determined only by the flow rate of the hydraulic oil passing through the hydraulic pump, or may be detected by a hydraulic motor, an encoder that detects the rotation of the winch, or the like.

In the crane and the control method of the crane, the adjustment of the output of the winch drive system may be adjusted by components other than the above-mentioned engine, hydraulic pump, hydraulic motor and control valve, or may be adjusted by a plurality of components. good.

In addition to the control mechanism according to the present invention, the crane is a conventional control means for adjusting the output of a winch drive system, for example, a control means for changing the capacity of a hydraulic motor according to the pressure of hydraulic oil supplied to the hydraulic motor. Etc. may be provided. The control mechanism according to the present invention can be configured to superimpose on the conventional control means to adjust the output of the winch drive system. In this case, the crane may be configured such that the theoretically superimposed output exceeds the actually possible output range and the output peaks or bottoms out.

In the crane and the crane control method, the control for not adjusting the output of the winch drive system when it is judged that the operation amount of the operator is small is the case where the output of the winch drive system is adjusted by a component other than the engine. Can also be applied to.

The present invention can be widely used in hydraulic cranes.

1,1a, 1b winch drive system 2,2a, 2b, 2c, 2d Control mechanism 11 Engine 12,12a Hydraulic pump 13,13b Hydraulic motor 14 Counterbalance valve 15 Control valve 16 Operating lever 17, 17a, 17b, 17c Controller 18 Pressure sensor 19 Flow sensor 20 Second pressure sensor W winch

Claims (10)

It is provided in an engine, a hydraulic pump driven by this engine, a hydraulic motor operated by hydraulic oil supplied from this hydraulic pump to drive a winch, and a flow path for supplying and discharging hydraulic oil to this hydraulic motor. A crane equipped with a winch drive system having a counterbalance valve and a control valve provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor and whose opening degree is changed according to an operator's operation amount.
A crane comprising a control mechanism for adjusting the output of the winch drive system at the time of winding according to the speed of the winch with respect to the operation amount of the operator at the time of winding. Based on the speed of the winch with respect to the operation amount of the operator at the time of winding, the control mechanism determines the speed at which the winch is wound and the speed at which the winch is unwound, which is assumed when the operation amount of the operator is constant. The crane according to claim 1, wherein the output of the winch drive system is adjusted so that the difference between the two is within a predetermined range. The crane according to claim 1 or 2, wherein the control mechanism reduces the output of the winch drive system at the time of winding so that the speed of the winch with respect to the operation amount of the operator at the time of winding is smaller. The crane according to claim 1, claim 2 or claim 3, wherein the control mechanism adjusts the rotation speed of the engine. The crane according to claim 1, claim 2 or claim 3, wherein the control mechanism adjusts the capacity of the hydraulic pump. The crane according to claim 1, claim 2 or claim 3, wherein the control mechanism adjusts the capacity of the hydraulic motor. The crane according to claim 1, claim 2 or claim 3, wherein the control mechanism adjusts the correspondence between the operation amount of the operator and the opening degree of the control valve. The crane according to any one of claims 1 to 7, wherein the control mechanism determines the speed of the winch based on the pressure and the flow rate of the hydraulic oil supplied to the hydraulic motor. The crane according to any one of claims 1 to 8, wherein the control mechanism does not adjust the output of the winch drive system when the operation amount of the operator is small. It is provided in an engine, a hydraulic pump driven by this engine, a hydraulic motor operated by hydraulic oil supplied from this hydraulic pump to drive a winch, and a flow path for supplying and discharging hydraulic oil to this hydraulic motor. A control method for a crane equipped with a winch drive system having a counterbalance valve and a control valve provided in a flow path for supplying and discharging hydraulic oil to the hydraulic motor and whose opening degree is changed according to an operator's operation amount. There,
A crane control method comprising adjusting the output of the winch drive system at the time of winding according to the speed of the winch with respect to the operation amount of the operator at the time of winding.

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